Foot Drop Stimulation via Piezoelectric Energy Harvester

Abstract

The design and implementation of a piezoelectric energy-harvesting system, aimed at stimulating the Tibialis anterior muscle to aid patients struggling with a foot drop disability, are investigated. A physical prototype designed to be installed inside a shoe sole, consisting of an energy-harvesting unit along with a power-management circuit and a functional electrical-stimulation circuit, is fabricated. The piezoelectric energy harvester (PEH) incorporated six layers of Polyvinylidene-Fluoride sheets to achieve a mean-charge generation of 65.25 μC/step and a peak power of 10.76 mW/step. A peak voltage of +80.0 V generation was achieved during a stomping motion. The electrical systems store, convert, and deploy 60 mA electric pulses at the desired frequencies to the target muscle. The finalized prototype is best-suited to prolong the duration of the charged batteries whilst in use. In a practical sense, it should be used alongside external-power sources to recharge the batteries installed in a foot drop stimulation device. The PEH in its current state is fully capable of solely powering blood pressure sensors, glucose meters, or activity trackers.